In general, scroll-type compressors form a compression chamber for compressing a compressible fluid, such as gas, between a fixed scroll and an orbiting scroll. By causing the orbiting scroll to orbitally move, the volume of the compression chamber is reduced to compress the gas in the compression chamber.
In such scroll-type compressors, in order to change the volume, i.e., the capacity, of the compression chamber at the start of compression, a method in which the heights of spiral-shaped wall members (teeth heights) provided upright on the fixed scroll and the orbiting scroll are changed and a method in which the spiral-end angles of the wall members are changed are known (for example, see Patent Literature 1).